“It is very hard if you say I’m going to go off an advisory group or not do ‘a, b, c’ because you disagree on one issue. Honestly, no one is going to agree with every president or prime minister on every issue. So I don’t want to overreact to it,” Dimon said.

Summers did not mince words in his response, also delivered on Bloomberg TV. He framed what he saw as a necessary opposition to Trump in much broader terms, saying Dimon’s argument that this was a single issue gone awry simply did not pass muster given the administration’s harsh stance on issues like immigration and international isolation on trade and security.

“Three points,” began Summers:

“1. Jamie referred to this as one issue. There’s an immigration ban, there’s arithmetic that doesn’t add up, there’s climate change, there’s crony capitalism and selective deals — this is hardly the first and only minor issue. This is the central part or philosophy — does the United States believe in a community of nations.

“2. Jamie should be prepared, and I would be prepared, and I hope any business leader would be prepared to offer advice to the president. That is a very different thing to lending your prestige and that of your company to joining an advisory board of his creation. That is accepting a presidential appointment.

“3. Where does this principle stop? Jamie says it’s one issue. What would cause him to back off? Look, our president is very different and I think the rhetoric on the left that compares him to leaders in Europe in the 1930s is frankly overdone.’

Summers went on:

“That said, at what point as a patriot is your allegiance to your country rather to your president? I’ve always thought of my allegiance as a patriot as being to my country. That’s why if I had been asked to support the kind of policies that are being advocated by this administration while in government I surely would have resigned. And make no mistake, the decisions business leaders make send a very powerful signal both to the rest of the world and the president. If Jamie and his colleagues on this advisory board resigned, not over the details of the Paris Agreement but over the philosophy that the United States no longer believes in cooperation with other nations in a community of nations, that would send a very powerful signal to the rest of the world and it would send a very powerful signal to the president and to the people at home.”

Lawrence H. Summers is the Charles W. Eliot University Professor and President Emeritus at Harvard University. He served as the 71st Secretary of the Treasury for President Clinton and the Director of the National Economic Council for President Obama.